Refrigerant pumping system



Jan. 1, 1935.

' s. E. KOPLAR REF-RIGERANT PUMPING SYSTEM Filed Sept. 29, 1932 4Sheets-Sheet 1 V U Jblomofl 6. Zop/an Jan. 1, 1935. S. E LAR 1,986,584

' REFRIGERANT PUMPING SYSTEM Filed Sept. 29, l932 4 Sheets-Sheet 2 I l g2 Solo 0% 6: 260a,.-

Jan. 1, 1935. s. E. KOPLAR 1,986,584

REFRIGERANT PUMP ING SYSTEM Filed Sept. 29, 1932 4 Sheets-Sheet :5

HI? I 70 dblomafl Jan. 1 1935. s. E. KOPLAR REFRIGER-ANT PUMPING SYSTEMFiled Sept. 29, 1932 4 Sheets-Sheet 4 VEcr U Patented Jan. 1, 1935UNITED STATES PATENT OFFICE REFRIGERANT PUMPING SlZSTEM Solomon E.Koplar, Chicago, 111. Application September 29, 1932, Serial No. 635,385

11 Claims.

This invention relates to refrigerant pumping systems and isparticularly concerned with improved pumping apparatus which embodiesnovel means for sealing and lubricating the pump parts, thereby makingthe apparatus particularly adapted for the pumping of a refrigerantHeretofore, pumps of the rotary type embodying pumping sectionsarrangedat an angle of have been used in connection with oil burners andExperiments with the above described pumps.

have disclosed that their inability to operate at the higher pressurewas primarily due to the angle between the pumping-sections, and that ifthe angle were changedso as to-.be greater than 90 and less than thefriction was materially decreased, thestarting characteristicsiwerehighly improved, and the higher pressures could be attained withoutdifiiculty.

Furthermore, it has heretofore been a problem to properly seal andlubricate the pump parts to maintain their operation over a long periodof time at the high pressure required in refrigerat ing systems.

Having the foregoing limitations in mind to:

the present pumps of this character, the present invention proposes toprovide a refrigerant. pump ing system wherein the pressure of therefrigerant is utilized to force oil into the pump for lubricating andsealing its parts.

It isa further object of the invention to provide a refrigerant pumpingsystem in which oil is taken up by the refrigerant in its passagethrough the pump, this oil being thereafter'separated out andreconducted to the pump for lubricating and sealing its parts.

-It is a further object of the invention to provide in a refrigerantpumping system, a pump of the angular rotary type having a chamber atthe junction of its pump sections, this chamber being adapted to receiveoil ,under pressure, whereby the pump parts are lubricated and sealed.

Another object of, the invention is to provide in a refrigerant pumpingsystem, means adapted to control the supply of lubricating oil to'thepump in accordance with the pressure of the refrigerant.

It is also an object of this invention to provide in a refrigerantpumping system, a pump of the,

angular rotary type which is so designed and constructed as to have lowfrictional losses, thereby enabling the pump to start easily and.operate at relatively high efiiciency. A still further object of theinvention is to provide in connection with a fluid pump, means forautomatically adjusting the pump in such a manner as to cause it tooperate with a relatively high order of efficiency, irrespective ofwhether the pump is furnishing the pumped fluid at high or low relativepressures. In accordance with the general features of this invention itis proposed to provide a refrigerant pump of the rotary angular typehaving the pumping sections disposed at an obtuse angle to each other.The housing defining the pumping sections is so constructed as to form achamber or cavity at the junction of the sections, this cavity orchamber being in communication with the pistons and cylinders of thepumping sections. under pressure and flows past the movable parts of thepump and is taken up by the refrigerant during its passage through thepump. "The oil is then separated from the refrigerant and is forced bythe refrigerant. back into the central chamber of the pump. In thismanner a circulatory oiling system is provided and the pump parts areeffectively lubricated and sealed.

As a further feature of this invention it is proposed to provide anunloading device for controlling the supply of oil to the aforementionedcentral chamber, so that this supply will be interrupted when the pumpis stopped and will again be established as soon as the pump is started.Thisis accomplished by means of an unloading device having a valvedisposed in the oil inlet to the pump, thisv valve being subjected onone side to the oil pressure within the central chamber of the pump andon the other side to the discharge pressure of the refrigerant. It willtherefore be observed that as soon as the pump stops, the decreasedpressure of the refrigerant will enable the oil pressure which has beenbuilt up in the pump chamber to close the valve, thereby disconnectingthe oil supply. Moreover, as soon as the pump is started, a check valveis opened due to the pressure at the discharge of the pump, and therefrigerant pressure which has been established in the system will actto cause the valve to open and admit oil under pressure to the centralchamber 'of the pump. In this manner automatic control of the flow ofoil to the pump is attained.

Other objects and features of this invention will more fully appear fromthe following detail description taken in connection with theaccompanying drawings which illustrate a single embodiment thereof, andin which Figure 1 is a side elevation of my improved Oil is introducedinto this chamber pumping apparatus embodying the features of thisinvention, the actuating means not being shown;

Figure 2 is a plan view of the apparatus;

Figure 3 is an elevation of a pump head for one of the pumping sections,in this instance the horizontal section, showing the inlet and .outletports therein;

Figure 4 is a longitudinal vertical section through the pump utilized inmy invention;

Figure 5 is a vertical transverse section through the horizontal pumpingsection of the pump, showing the passageway to the horizontal bores,taken' substantially on line V--V of Figure 4;

Figure 6 is a similar sectional view through the angularly disposedpumping section, taken substantially on line VIVI of Figure 4;

Figure 7 is a sectional view through the head for the horizontal pumpingsection, taken substantially on line VIIVII of Figure 3;

Figure 8 is a longitudinal section through the unloading device, showingthe details of its interior, taken substantially on line VIII.Vl1I ofFigure 1;

Figure 9 is a view similar to Figure 3, showing a modified portarrangement; and

Figure 10' isan enlargedfragmentary section showing details ofvalvemeans to interconnect an auxiliary port to the outlet port, takensubstantially on line-XX of Figure 9.

As shownon'the drawings? As illustrative ofmy' invention, I have chosento show'in Figure 1, pumping apparatus embodying the features of myinvention, which are adapted for use in a refrigerating system. Since myinvention is concerned with the pumping apparatus and devicescooperating therewith in the pumping operation, it has not been deemednecessary to show the various instrumentalities comprising theevaporating system, as these would be of conventional construction, andare well known in the art.

. The refrigerant pumping system of my invention broadly embraces arefrigerant pump generally indicated at A, which may be driven by anysuitable power means (not shown) such as an electric motor or the like..separating means 3 for separating the oil from the refrigerant andapplying pressurethereto, and an unloading device C for controlling thesupply of oil to the pump in accordance with the pressure ofthe'refrigerant discharged from the pump.

The pump structure .comprises cylindrical housings 10 and 11 which aredetachably secured together at their inner ends by means of cooperatingflanges 12 and 13 and bolts 14 in such a -manner that the housings willbe disposed at an angle to each other, in this instance, an angle ofsubstantially 105. Removably secured to the outer ends of the housingsby means of bolts 15 are heads 16 and 1'7 which facilitate pipeconnections to the pump in a manner that will be subsequently describedin detail. The entire pump assembly is supported on a base structure 18which is secured to a flange portion 19 on the housing 10 by means ofbolts 20. The housings and heads of the pump are provided with suitablefins 21 and 22 which are suitably disposed to be engaged by circulatingair, whereby the pump may be aircooled.

At the junction of the housings 10 and 11, a chamber 23 is formed.Rotatably disposed between this chamber and the head 16 is a cylinashoulder 25 which is formed in a central bore 26 of the cylinder, thisshoulder abutting the end of a shaft' 27 having its other end contractedat 28 to extend through the head 1'7. The contracted end 28 is threadedfor receiving a nut 29 by means of which a shoulder 30 is drawn tervalsabout the central axis of the cylinder,.

each of these bores being adapted to reciprocably receive therein aplunger 33 which is of hollow construction and closed at its outer endby means of a plug 34. N

The outer end of the cylinder 24 is closed by a plate member 35 which issecured at its center by means of a threaded end 36 of a shaft 37, whichextends through the plate and threadedly engages the cylinder in such amanner that when the shaft is screwed into the cylinder, a shoulder 36is drawn against the outer side of the plate.

Suitable ports 39 are provided in the plate 35, and each of these portscommunicates with one of the bores in the cylinder.

' The shaft 37 extends outwardly through the head 16 and is rotatablysupported in a bearing bracket 40 which together with the head 16 issecured to the housing 10 by the bolts 15. This shaft adjacent its outerend has fixedly secured thereto a plurality of fan blades 41 which, whenthe pump is running, will circulate air against the 'fianges on thehousings and heads. The outer end of this shaft is connected through asuitablecoupling 42 to the driving shaft 43 of an electric motor or anyother suitable power means.

The housing 11 contains a similar pumping structure which comprises acylinder 44 having a central bore 45 which surrounds the bearing portion31 of the shaft 27, whereby the cylinder is rotatably mounted. Thiscylinder is held against axial displacement by means of the head 17 andits abutment at its inner end against the inner end of cylinder 24. Thecylinder 44 is likewise provided with a plurality of angularly spacedbores 46 which are adapted to reciprocably receive therein plungers 47.These plungers are of hollow construction and are closed at their irmerends-by suitable plugs 48. The outer end of the cylinder 47 is closed bymeans of a plate 49 which surrounds the portion 31 of. the shaft 27 andis secured to the end of the cylinder by means of any suitable fasteningmeans such as pins. This plate is provided with a plurality of portopenings 50, each of which is in communication with one of the bores 46.

The plungers in the corresponding bores of the two cylinders are rigidlyconnected-together at their adjacent ends by means of an angularconnection 51 so that, when the shaft 3'1 and cylinder 24 are rotated,the angularly disposed plungers will reciprocate in their respectivebores and transmit the rotative movement of cylinder 24 to the cylinder44, all in a manner well understood in the art. During the rotativemovement of these cylinders, the interconnected pairs of plungers willbe reciprocated in their respective bores and produce a pumping action.

The head 16 is provided at one side with an inlet passageway 52 adaptedto be connected by suitable piping 53.to a suction connection 54 whichis adapted to be connected to the vacuum inletpassageway a portpassageway 55 extends through the head and terminates at the inner facethereof in an arcuate channel 56 which is concentric with-the axis ofthe cylinder 24 and in the path of the ports 39 which communicate witheach of the cylindrical bores 32 therein. At its opposite side the headhas an outlet passageway 57 which is adapted for connection to adischarge pipe 58 and communicates with a port passageway 59 extendingthrough the head and terminating in the inner face thereof in an arcuatechannel 60which is disposed on the opposite side of the axis of the headfrom the channel 56. The channel 60 is likewise disposed in the path ofthe ports 39 which communicate with the respective longitudinal bores ofthe cylinder. In

- substantial quadrature to the inlet and outlet passageways, anotherpassageway 61 is arranged, this passageway being adapted for connectionto a suitable pipe 62 which is connected to a vacuum gauge 63. Thepassageway 61 is in communication through a port opening or passageway64 with the channel 56. With this arrangement, it

' will be appreciated that the vacuum gauge will indicate the vacuumorsuction on the intake side of the pump.

The head 17 is constructed in a similar manner to the head 16, exceptthat in the case of head 17, it is not necessary to provide a vacuum orsuction connection to the gauge. Referring to Figure 6, the head 17 isprovided with an inlet passageway 65 which is adapted for receiving asuitable pipe connection 66 and communicates through a port passageway67 with an arcuate channel 68 which is concentric with the axis of thecylinder 44 and in the path of the ports 50 which communicate with therespective bores46 therein. On the opposite side of the head 17 from theinlet passageway is an outlet passageway 69 which is adapted for asuitable pipe connection 70 and communicates with a port passageway 71which extends through the head and terminates in an arcuate channel 72which is likewise disposed in the path of travel of .the port openings50 and is concentric to the axis-of the cylinder 44.

The unloading device C comprises a sectional housing in which therespective sections are secured together by end clamping members 73 and74 which are tightened in operative position by means of clamping bolts75. Withinthe housing is a plunger or piston 76 which is disposed forreciprocable movement within a chamber-77. The

- lower side. of the plunger 76 is connected to ,a stem 78 which carriesat its lower end a valve 79 which is cooperatively associated with avalve seat 80. This valve is disposed between an oil inlet connectionpipe 81 and an oil outlet connection 82 which communicates withthe'chamber 77. The upper surface of the piston 76 is in communication witha chamber 83 having an inlet pipe con-.

nection 84 forming an inlet for refrigerant. Abo've the chamber 83 is achamber 85 which is in communication with a pipe connection 86 whichforms an outlet for the refrigerant. Intermediate the chambers 83 and 85is a downwardly seating check valve 87 whichis arranged tocooperate witha seat 88.

The separator comprises a tank 89 having an inlet connection 90 in itstop and an outlet connection 91 also in its top which is adapted forconnection to the pressure side of the refrigerating system. A pressuregauge 92 is secured in the top of this tank to indicate'the refrigerantpressure. The bottom of the tank 89 contains an outlet connection 93,the purpose of which will later be explained.

Referring to Figures 1 and 2, it will be observed that the inletconnections 53 and 66 of the pump housings are connected togetherthrough a pipe connection 94 and that the discharge or outletconnections 58 and 70 are respectively connected through pipes 95 and 96to a T connection which is in communication with connection 84 of theunloader. The connection 86 of the unloader is connected through pipe 97to the connection 90 of the separator. The connection 81 of the unloaderis connected to connection 93 at the bottom of the separator tank bymeans of a pipe 98 and the connection 82 from the unloader communicateswith the chamber 23 at the junction of the pump housings.

The operation of my refrigerant pumping system will be substantially asfollows:

The pump is started by means of suitable control equipment for startingthe power means which drive the pump, the power means being so connectedas to drive the shaft 37 in a counter clockwise directionwhenfacing theouter end of housing 10. As the shaft 37 rotates it carries;

plungers 33 and 47 to the cylinder 44. Rotation of .these cylinders willcause the pairs of plungers to be reciprocated in their respectivebores. In the described construction, six plungers are provided in eachcylinder so that when the lowermost plungers have reached theiroutermost limit of travel, the uppermost plungers will have reachedtheir innermost limit of travel, and the other plungers will be disposedat intermediate compression and suction positions, each plungersuccessively' reaching its position of full suction in the topmostposition as shown in Figure 4 and its full compression position when it.-'reaches the lowermost position shown in Figure 5'. The same actiontakes place as regardsthe action of the plungers within housing 11.

Due to this action of the plungers, refrigerant will be drawn from thecommon: suction connection 54 and discharged through connections 58 and.70, through pipes 95 and 96 respectively to the common T connection 84into chamber 83 of the unloader. This pressure of refrigerant lifts thecheck valve 87 to enable refrigerant to pass refrigerant acts upon theplunger 76 which is moved downwardly thereby to open the valve 79 andenable oil to flow from the tank 89 through connection 93. pipe 98 andconnection 81 past valve 79 of the unloader and thence into chamber 77and out of the pipe connection 82 into the chamber 23 of the pump.

It will be observed'that due to the pressure of refrigerant in the tank89, the oil will be forced into the pump under pressure, and that as thepump operates, the -oil will-engage the pistons and cylinder walls andtravel into the refrigerant pumping portion of the cylinder, where it ispicked up by the refrigerant and carried to the tank 89 where it willsettle'to the bottom by virtue of the' action of gravity thereon. Sincethe pressure of oil in the chamber 23 acts upon the bottom side of theplunger 76 in the unloader, it will be apparent that as soon as the pumpis stopped, thereby enabling the pressure in the refrigerating system toclose the check to continue forcing oil into the chamber 23. Howeversince the closing of the check valve and stopping of the pump relievesthe pressure 'on the upper surface of the plunger '76, the oil pressurefrom tank 89 will act to close the valve 79 and shut off the supply ofoil to the chamber 23.

In the foregoing description I have described one arrangement of inletand outlet ports for the heads 16 and 1'7, and while this arrangementhas proved to be very satisfactory, a modified arrangement is disclosedin Figures 9 and 10 which embraces an auxiliary valve arrangementwhereby the starting of the pump is facilitated.

Referring to Figure 5, for example, it will be observed that, when thepump is stopped, the rotatable cylinder may come to rest in a positionsuch that the port 39 of at least one of the bores, which bore containsa plunger 33 that has started on its compression stroke, has not reachedthe channel 60. Consequently, oil may be forced into this bore from thechamber 23, and, since there is no outlet from the bore in this positionof the cylinder, the bore ahead of the plunger will become filled withoil and tend to lock the pump against easy starting.

To prevent such a condition, it is contemplated that the modified formof head as shown in Figures 9 and 10 may be used, if desired. Thisfeature although shown as applied to head 16, would.

also be incorporated in head 1'7. Parts in the modified form, whichcorrespond to the head disclosed in Figure 3, are indicated by thesamenuway 100 by a spring 104. This spring at its inner end engages thevalve member and at its outer end bears against a plug 105 threaded intothe outer end of the valve chamber. This plug also provides 'anadjustment whereby the spring may be compressed more or less to causethe valve to open at a greater or less pressure, as desired.

With this modified head, when the pump is stopped and the cylinders arein the position transmitted to the valve which is thereby maintainedclosed while the pump is, running. The modified head arrangement inaddition to enabling the pump to start easily, also operates auto-'matically to change the characteristics of the outlet connections, whenthe pump operation is changed from high pressure to low pressure, andvice versa. Due to the effect of this change in the characteristics ofthe outlet connections, a high pump operating efliciency is attainedwhen t the pump is operated at low pressure.

Referring to Figures 9 and 10, the channel 60 is designed and positionedto give the best opcrating efiiciency for the pump, when the pump isoperating at high pressure. It has heretofore been observed that with asingle fixed outlet port of such character, the efiiciency of the pumpis materially decreased, when operating at comparatively low pressures.obtain in effect a longer channel 60, which has been found to give ahigh pump ef iciency at the lower pressures, the auxiliary channel 99,its as sociated valve mechanism and passageway 10.2 are provided.

Now, when the pump is pumping fluid-into a Therefore, in order to highpressure system, the system pressure is communicated to the lower sideof the valve 103,

through the channel '60, passageway 102 and' valve chamber 101. Theupperside of this valve is subjected to the partially compressed fluidin the bore which is in communication with the auxiliary channel 99 andpassageway 100; and since the force acting on the upper side of thisvalve is less than that acting on'the underside,

the valve will remain closedf Thus, the -fully' compressed fluid passesout through channel-60,

which is designed to give a high efficiency at the high pressureoperation of the pump.

At low system pressure, thepressure acting upon the underside of thevalve 103 is less than that acting on the upper side thereof, and thevalve will open to discharge the partially compressed fluid in the borein communication with the channel 99. plunger therein is not required tofully compress the fluid to a higher pressure as the bore moves intocommunication with the channel 60. This action of the valve 10 3 duringlow pressure op- This bore being relieved, the.

-eration decreases the-amount of power required,

and consequently increases the efiicienoy of the pump over that whichwould otherwise be obtained.

It will be appreciated from the foregoing that the refrigerant pumpingsystem of my invention provides novel pumping apparatus which is soconstructed that it will operate with very lbw frictional losses; whichutilizes the refrigerant pressure to force the lubricant to circulatepast the pump parts to lubricate and seal the same; a system havingpumping apparatus embodying novel lubricating and sealing arrangementfor 'the' parts of'the pump; a system wherein the supply of lubricant tothe pump is controlled in accordance with the pressure of therefrigerant being pumped; and a pump having high efiiciency irrespectiveof whether it isoperating at a high or low pressure.

While I have shown and described my invention in a preferred form,changes and modifications in structure. and arrangement may be madewithout departing from the spirit and scope of the invention and I,therefore, do not, limit my ber, whereby the pump parts are lubricated,an ,7

outlet from the pump sections, means connected to said outlet forseparating the refrigerant and oil taken up by the refrigerant in itspassage through the pump sections, the separated oil being subjected tothe pressure of the refrigerant, and a connection from said meansto theoil supply connection to conduct theseparated oil back to said chamber.

, 2. In a refrigerating system; a refrigerant pump having its partslubricated, a connection :to supply oil under pressure to the pumpparts,

a main discharge connection from saidpump, a check valve in saiddischarge connection, a

t 10 plungeractuated valve to control the supply of the plunger, wherebythe -oil supply to the pump spaced bores, pistons reciprocable in saidbores,.

is automatically closed when the pump is shut down and opened when thepump is running.

3. ma pump of thecharacter described a rotatable member having aplurality of angularly a discharge connection from said pump, means toconnect each bore to the discharge connection when its associated pistonis substantially at the end of its discharge stroke, andmeans operative,when the pump is stopped, to prematurely connect the bores to thedischarge connection.

4. In a refrigerant pumping system, a pump having a cylindrical housing,a cylinder rotatable in said housing, said cylinder having a pluralityof longitudinal bores angularly spaced at regular intervals about thecenter-line of rotation of the cylinder, pistons reciprocable in said"bores when the cylinderis rotated, an outlet passage from the pump,means to connect each bore to the outlet passage as its associatedpistonap- -proaches full compression position, and means to connect all thebores having pistons on their' compression stroke' to(the outletpassage, when the pump is stopped.

5. In a pump of the character described arotatable member having aplurality of angularly spaced bores, each bore having an end defining.

, passage in communication with the main and auxiliary ports, and valvemeans arranged to connect and disconnect the auxiliary port relative tothe outlet passage.

- .6. In a pump of the character described a rotatable member having aplurality oflangularly spaced bores, each bore having an end defining,

an opening, tall-said openings being disposed on a common'axis circle, ahousing for said member defining a main port and an auxiliary portdisposed in the line of travel of said openings, the auxiliary portbeing arranged to register with the openings prior to the main port, anoutlet passage in communication with the main and I auxiliary ports, avalve operative to connect and disconnect the auxiliary portrelative tothe out let passage, one face of the valve being subject to pressure inthe auxiliary port and the opposite face thereof being subject topressure in the main port, whereby the valve will be closed,

' when the pumpisrunning, and open, when the .70 Pump is s pf d withbore openings inrgistra- -tion with the main'and auxiliaryportsrespec--- tively. I L

'7. An unloading device adapted for use in connection with a fluid pumphaving its parts lubri cated from an oil pressure supply, said devicechamber, each of said chambers having an inlet connection and an outletconnection, the fluid chamber having its inlet adapted for connection tothe pump discharge, and the oil chamber its inlet for connection to theoil supply and its outlet to the parts to be lubricated, a valve tocontrol the flow of oil through the oil chamber, and a piston connectedto said valve and reciprocable in the connection between said chambers,one side of the piston being subjected to the fluid pressure and theother side to oil pressure, whereby the valve is closed, when the oilpressure predominates and opened, when the fluid pressure predominates.

8. In arefrigerant system, a refrigerant pump comprising a housingdefining a fluid pressure chamber interconnected with an oil pressurehaving its parts lubricated, an oil supply connection to the pumpparts'subject to the system pressure, a main discharge connection fromthe pump, a check valve'in said connection, and a plunger actuated valveto control the supply of oil to the pump,'one side of said plungerbeing, subjected to the pump discharge pressure and ative to compress afluid, an outlet passagefor the compressed fluid from said elements,valve means to control the flow of compressed fluid into the outletpassage when pumping at high pressure, and auxiliary outlet meansactuated by the outlet pressure to augment the action of said valvemeans, when pumping at low pressure; said auxiliary outlet beingconnected to said pump to deliver fluid at less than' fully compressedpressure.

10. In a pumping device having elements operative to compress a fluid,amain outlet passage forthe compresesdfluid'from said elements, anauxiliary outlet associated with the main outlet and adapted to deliverpartially compressed fluid, and valve means tocontroi the flow of fluidfrom said elements to said-outlets, said means being automaticallyoperable in accordance with the deliverypressure'ofthe compressed fluid,whereby the auxiliary outlet functions when the pump is delivering thecompressed fluid at a relatively low pressure. \r

11. In a pump of the character described, a rospaced bores, each borehaving an end defining an opening, all said'openings being disposed on acommon axis circle, a housing for said member defining a main port andan auxiliary port disposed in the line of travel of said openings, the

auxiliary port being arranged to register with the openings prior to themain port, an outletpassage in communication with the main and auxiliaryports,'and valve means arranged to connect and disconnect the auxiliaryport relative to the outlet passage, said valve means being autatablemember having a plurality of angularly tomatically actuated to openposition, when the pump is operating at low pressure, and closedposition when the pump is operating at high SOLOMON E. KOPLAR.

